A combination of three experimental Bristol-Myers Squibb hepatitis C drugs appeared to be highly effective, according to data from a mid-stage clinical trial, keeping the company in the race for developing an all-oral treatment regimen for the serious liver disease. The combination therapy, which involves three direct acting antiviral drugs that each attack different targets needed for replication of the hepatitis virus, achieved cure rates as high as 94 percent when given for either 12 weeks or 24 weeks, according to results of the small study. Current treatment regimens for the disease still include the older, difficult-to-tolerate drugs interferon and ribavirin and are typically taken for either 24 weeks or 48 weeks. When used with newer drugs, they have cure rates as high as about 80 percent. Several companies are developing hepatitis C regimens that do not include interferon - which is given intravenously and often causes miserable flu-like symptoms - while also pursuing much shorter treatment durations.